MENTOR, Ohio (AP) — Reaching for the finish line, Republican Mitt Romney and President Barack Obama embarked Saturday on the final 72-hour haul of their long, grinding quest for victory, swatting at one another over what should motivate Americans to vote, which candidate they can trust and offering dueling pictures of what the next four years should bring.

Romney sprinted through a New Hampshire-to-Iowa-to-Colorado day faulting Obama for telling supporters a day earlier that voting would be their “best revenge.”

“Vote for ‘revenge?”’ the GOP candidate asked in New Hampshire, oozing incredulity. “Let me tell you what I’d like to tell you: Vote for love of country. It is time we lead America to a better place.”

The Republican nominee sounded the same message in Iowa and released a TV ad carrying the same message.

Obama, campaigning in the uber-battleground of Ohio, countered with a final reminder that Tuesday’s election is “not just a choice between two candidates or two parties, it’s a choice between two different visions for America.” The president offered himself as the candidate voters can trust, renewing his criticism of Romney for what he said were misleading ads suggesting that automakers were shifting U.S. jobs to China.

“You want to know that your president means what he says and says what he means,” Obama told a 4,000-person crowd in northeast Ohio. “And after four years as president, you know me.”

The president urged voters in an overflow room to shepherd their friends, neighbors and girlfriends to the polls to vote early, tacking on this very practical caveat: “You should convince them to vote for me before you drag them off to the polls.”

Campaign spokesman Jennifer Psaki said the president’s revenge comment was nothing more than a reminder that if voters think Romney’s policies are “a bad deal for the middle class, then you have power, you can go to the voting booth and cast your ballot.”

Whatever their motivation, 27 million Americans already have cast ballots around the country.

On the last day of early voting in Florida, voters at some sites in Miami-Dade and Broward counties were waiting up to four hours to cast ballots. Sen. Bill Nelson, D-Fla., asked his state’s Republican governor to extend early voting at least through Sunday, citing “an untold number of voters being turned away or becoming too discouraged to vote.”

Vice President Joe Biden spoke for all sides when he told a crowd in Arvada, Colo.: “Man, I’m so ready to win this election.”

Before leaving Washington, Obama tended to presidential business as he led a briefing at the government’s disaster relief agency on the federal response to Superstorm Sandy. He said the recovery effort still has a long way to go but pledged a “120 percent effort” by all those involved.

“There’s nothing more important than us getting this right,” Obama said, keenly aware that a spot-on government response to the storm also was important to his political prospects. Then he began his own three-state campaign day.

After holding mostly small and midsize rallies for much of the campaign, Obama’s team is holding a series of larger events this weekend aimed at drawing big crowds in battleground states. Still, the campaign isn’t expecting to draw the massive audiences Obama had in the closing days of the 2008 race, when his rallies drew more than 50,000.

In a whiff of 2008 nostalgia, some of Obama’s traveling companions from his campaign four years ago joined him on the road for the final days of his last campaign. Among them are Robert Gibbs, who served as Obama’s first White House press secretary, and Reggie Love, Obama’s former personal aide who left the White House earlier this year.

Likewise, virtually Romney’s entire senior team left the campaign’s Boston headquarters to travel with Romney for the contest’s final three days. Their presence for the campaign’s waning hours is an admission that the strategy and planning is largely complete. His schedule has been set, the ads have been placed and Romney’s message has been decided.

The tight inner circle that has worked with him for several years in most cases plan to enjoy the final moments on the campaign trail at Romney’s side.

“It’s been a long road,” Ann Romney told reporters aboard the campaign plane, offering breakfast pastries to Secret Service agents and reporters alike. After campaigning on her own for the past month, she joined her husband for the final swing.

After his Saturday morning rally on the New Hampshire seacoast, Romney targeted Iowa and then Colorado. He shifted an original plan to campaign in Nevada on Sunday in favor of a schedule likely to bring him back to Iowa, Ohio, Pennsylvania and Virginia.

Obama’s Saturday itinerary had him heading from Ohio to Milwaukee and Dubuque, Iowa, and ending the day in Bristow, Va. On Sunday, he was taking his campaign to New Hampshire, Florida, Colorado and Ohio.

GOP running mate Paul Ryan was in Ohio and Pennsylvania, where he, too, took issue with Obama’s “revenge” comment.

“We don’t believe in revenge; we believe in change and hope,” he said in Ohio. “We actually do.”

Biden, in Colorado, worked in a new dig at Romney tied to this weekend’s shift back to standard time: “It’s Mitt Romney’s favorite time of year, because he gets to turn the clock back. He wants to turn that clock back so desperately. This time he can really do it.”

Polling shows the race remains a tossup heading into the final days. But Romney still has the tougher path; he must win more of the nine most-contested states to reach 270 electoral votes: Ohio, Florida, Virginia, North Carolina, Colorado, Nevada, Wisconsin, Iowa and New Hampshire.

Romney has added Pennsylvania to the mix, hoping to end a streak of five presidential contests where the Democratic candidate prevailed in the state. Obama won Pennsylvania by more than 10 percentage points in 2008; the latest polls in the state give him a 4- to 5-point margin.

After months of attack ads, the Obama and Romney campaigns both closed out their campaigns with some upbeat new messages while their allied independent groups continued on a largely negative note.

Obama’s campaign was airing a 1-minute ad, “Determination,” in all the major battleground states. Obama ticks through his plans to boost manufacturing, invest in education and job training, and bring down the deficit in part by asking wealthy people to “pay a little bit more.”

Romney’s campaign was running an ad across the battleground states titled “Clear Path,” which pulled clips from the third presidential debate where Romney laid out how his presidency would differ from Obama’s.